This invention relates to multicast routing.
Computer networks enable computers on opposite sides of the world to exchange e-mail, internet web-pages, chat messages and other electronic information. Typically, the electronic information is stored in packets. A packet is like an envelope with a return address (the packet source) and a mailing address (the packet destination). Much as an envelope reaches its mailing address via a series of post offices, a network packet reaches its destination by winding its way through different computers in the network.
One type of network computer is known as a router. When a router receives a network packet, the router typically tries to figure out how to send the packet to its destination in the least amount of time.